Aligning device for boat trailers



[56] References Cited UNITED STATES PATENTS 2,827,304 3/1958Backus......................... 3,111,236 11/1963 1rey....... 3,447,8156/1969 Primary Examiner-Albert J. Mak Attorney-Keith S. BergmanABSTRACT: Paired opposed upwardly extending guides are Paul PlummerPotlatch, Idaho 83855 AppLNo. 773,126

Nov. 4, 1968 [45] Patented Dec. 15,1970

United States Patent [72] Inventor [22] Filed ed for placement at therear of a boat trailer to aid in pen the trailer by flotation. The

spaced distance and indepenly biased toward each other to allow entry gthe boat in a igned position relative the guides during n process. The 1guides contact the boat by rotatably mounted guiding rollers.

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PATENTEIJuemssm 3547285 SHEET 1 BF 2 AT TORNE Y ALIGNING DEVICE FORBOAT'TRAILERS This invention relates generally to a guideto aid inplace- 5 ment of a boat by flotation upon a trailer and moreparticularly to such a guide providing independent opposed, mechanicallybiased arms to maintain the boat symmetrically therebetween duringloading.

2. Description of the Prior Art Light boats are often stored upon andcarried between place of storage and use by light trailers. Suchtrailers normally provide a rigid frame joumaling depending wheels forlocomotion and are adapted to rollably receive a carried boat, generallyby the keel, and maintain it in a symmetrical upright fashion thereon.

With the use of such trailers it becomes necessary to load and unloadthe boat therefrom when it is desired to place it in a body of water.The unloading operation is commonly accomplished by releasing the boatfrom attachment to the trailer and backing the trailer rather rapidlydown an inclined ramp into the body of water with a rather sudden stopwhen the boat is in approximate position to leave the trailer by itsinertia and enter the water.

The loading operation is more difficult. It generally is accomplished byplacement of the trailer in the body of water at a level wherefrom theboat may be substantially floated onto the trailer. It is necessary,however, to position the boat symmetrically upon the trailer and move ittherealong. To aid in this operation most boat trailers are providedwith multiple keel rollers extending along a linear course in the centerof the trailer over which the keel of the boat normally will pass. Somemechanical means of aiding the pulling of the boat upon the trailer isusually provided in the forepart or tongue of the trailer, most commonlya winch device of some sort to appropriately multiply force supplied totheboat. In this opera tion, alignment is not easily accomplished withthe normally small keel rollers.

It has heretofore become known to provide supports in addition to thekeel rollers to aid in this placement. Such devices as have become knownmay be divided generally into a first class comprising guides rigidlymounted relative the trailer, and a second class providing guidesmovably mounted in one fashion or another.

The instant invention is quite readily distinguishable from members ofthe first class as they provide no automatic adjustment for particularsizes and shapes of boats or for the varying cross-sectional sizes of anindividual boat passing therebetween and because of this limitation,they generally have a great potentiality of damaging the boat duringplacement or else provide no alignment potentiality of any substantialbenefit.

Members of the second class that are only discretely movable relativethe trailer frame provide, substantially the same problems or elserequire continuous adjustment for individual boats and varyingconfigurations of the same boat passing thereover. Other members of thissecond class providing continuous motion have in general not provided acontinuous mechanical bias tending to maintain a boat in symmetricalposition during its passage thereover or else have provided some meansof contact with the boat during its passage over the aligning devicethat tends to damage the boat surface. Such known devices also have notbeen of such form as to exist in a unitized structure that may bereadilyattached to existing trailers without substantial modification oralteration of either the trailer or aligning device. Other members ofthis second class also have notbeen adaptable for use upon boats ofvarying configuration without major adjustment either before or duringuse. My invention provides solutions to all of these problems.

Summary of Invention My invention provides a unitized, pivotablymounted, mechanically biased guide to be positioned in opposed pairs atthe rearward part of a boat trailer to rollably contact the boat hulland aid in symmetrically positioning it during placement upon thetrailer by flotation.

To structurally accomplish this function, I provide a housing pivotablymounting an upwardly extending elongated guide arm carrying a rollerstructure in its uppermost part to contact a boat hull. The guide arm isbiased by a torsion spring to a substantially vertical position butmovable laterally downward by appropriate force to a substantiallyhorizontal position with reference to-the housing. Mechanical limitationprevents the guide arm from rotating upwardly further than the vertical.The roller structure carried by the guide arm is of cylindrical shapewith axis of rotation substantially parallel to the surface of a craftas it passes thereover.

Two of these guide units are mounted in the rearward medial part of anormal boat trailer with the guide arms very nearly adjacent andextending upwardly. The mounting of the housing upon the trailerstructure may be accomplished by bolting, welding or any like process.The length of the guide arms is such that the roller structuresextending a substantial distance above the surface of the boat trailerso that they will contact the boat hull in its forwardmost portion asthe bow of the boat approaches the guides to continually align the boaton the trailer during its passage therepast.

In providing such a mechanism it is:

A principal object of my invention to provide a guide system for boattrailers with upwardly extending, paired, opposed, mechanically biasedguides adapted to contact the forward portion of the hull of a boat asit approaches a trailer and maintain the boat hull in a substantiallysymmetrical position relative the trailer during its passage forwardlyover the guide structure.

A further object to create such a guide system that contacts a boat hullby means of rotatably mounted rollers having axis of rotationsubstantially perpendicular to the line of travel of the boatthereacross to prevent damage to the boat during passage over therollers.

A further object of my invention to provide such a guiding device thatis automatically movable by reason of its mechanism and bias toaccommodate boats of varying sizes and to be continually incommunication with the hull of a boat during passage of the variouscross-sectional shapes thereof over the guiding device. 7

A still further object of my invention to provide such a guidingstructure that is self-contained in a relatively small unit that may bereadily fastened to and used upon ordinary boat trailers of commercewithout any substantial modification of either my invention of the boattrailer.

A still further object of my invention to provide such a device that isof new and novel design, of rugged and durable nature, of simple andeconomic manufacture and one that is otherwise well adapted to the usesand purposes for which it is intended.

Other and further objects of my invention will appear from the followingspecification and accompanying drawings which form a part of thisapplication. In carrying out the objects of my invention, however, it isto be understood that its essential features are susceptible of changein design and structural arrangement with only one preferred andpractical embodiment being illustrated in the accompanying drawings, asrequired.

BRIEF DESCRIPTION OF DRAWINGS In the accompanying drawings which form apart of this application and wherein like numbers of reference refer tosimilar parts throughout:

FIG. 1 is an isometric view of an ordinary boat trailer of commerce withmy invention in place thereon.

FIG. 2 is an orthographic view of my invention, looking from the medialline of a boat trailer laterally outward, showing particularly themechanical biasing of the guide arm.

FIG. 3 is a diametrical cross-sectional view through the guide arm toshow the mounting of the roller thereon, such as would be seen on theline 3-3 of FIG. 6, when looking in the direction indicated by thearrows on this line.

' FIG. 4 is a cross-sectional view of the pivotably mounting of theguide arm on the guide housing, such as would be seen on the line 4-4 inFIG. 5 when looking in the direction indicated the arrows thereon. FIG.5 is a partial side view of my invention showing particularly the sideof the mounting structure.

FIG. 6 is a similar view to that of FIG. 5 with the near side of thehousing-removed to show in more detail the internal structure of myinvention from this aspect.

'I FIG. 7 is an orthographic top view of the chain plate showirigparticularly the method of adjustable fastening of the limitchaintherein.

' .DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawingsin more detail and particularly to that of FIG. 1, it will there be seenthat my invention generally comprises housing structure 10 pivotablymounting guide arms 11 with biasing structure 12 and motion limitingstructure 13 extending therebetween to regulate the motion of the guidearm relative the housing.

LI-Iousing structure 10 is formed with similar paired opposed sides l4,l5 rigidly joined by angle iron crosspiece' 17 and fastening plate 18.Similar opposed cooperating holes gl 6tare provided in the upper portionof each side to receive guide arm axle 20. Plural tension adjustmentholes 19 are prog i ded in side to aid in the adjustable biasing of theguide arm structure as hereinafter more particularly described. Theseelements preferably are formedof metal and joined by welding;

Guide arm axle 20' extends through holes 16in sides 14, 15 and'somedistance laterallybeyond side 15 to allow releasable attachment to thehousing structure with aid of collar 21. This collar 21 is the annularstructure shown, welded to side 15 and provided with diametricallyextending hole 22, cooperating with the hole 23 in guide arm axle 20 toreceive cotter key 24 vtherethrough to maintain the entire structure inrigid but releasable position.

".Guide am structure 11 comprises pipelike guide arm bushing 25pivotably mounted upon guide arm axle 20 between sides 14, 15. Guide arm26 is relatively elongate, rodlike elerrierit structurally communicatingwith one end of the outer peripheral surface of arm bushing 25,preferably by welding, andjextending substantially perpendicularlytherefrom. The guide arm in its outer portion is provided with thepivotably mounted guide roller 27 maintained in rotatably positionthereon with washers 28 on either side thereof between keeper rings 29carried in grooves 30; in the surface of the guide arm. An outwardmostnipple 31 is provided to receive additional auxiliary structures (notshown), if such be desired t'o' further aid in aligning boats of largerdimensions Chain retainer ring 32 is structurally attached to the guidearm immediately below the roller to receive the limiting chain.

Biasing structure 12 includes helical torsion spring 33, having aninternal void allowing positioning of the spring about the outer surfaceof guide arm bushing 25. Fastening arm 34 of this spring extendsradially outward for a distance to teri'riinate in guide arm hook 35adapted to appropriately communicate with the guide arm. The other endof this spring terininates in adjustment arm 36 extending radiallyoutward a distance slightly greater than the external surface of thespring body 33. This adjustment arm is adapted to communicatewith collar38 threadedly carried by adjustment bolt 39 engaged in one of the pluraltension bolt holes 19 in side 15.

It is to be noted that these adjustment holes are positioned i'rifaspaced fashion at the same radial distance from the axis of pivot ofguide arm bushing 25 so that adjustment arm 36 of the torsion springwill always contact the adjustment collar, but yet the tension in spring33 may be adjusted to cause varying forces upon guide arm 26 dependingupon the positioning of adjustment bolt 39 in one of the tension boltholes 19.

Motion limiting structure 13 includes chain 40 extending between chainretainer 32 on guide arm 26 and chain-fastening plate 18 carried by thehousing structure. The chainfastening plate is provided with theholelike fastening structure providing circular hole 41 communicatingwith elongate slot 42 so configured that the chain will pass through thecircular hole but when one link is carried in slot 42 as illustrated inFIG. 7, the next link will not pass therethrough. A small retainer plate43 is pivotably mounted by nut-bolt combination 44 on one surface of thechain retaining plate to be pivotably movable over circular hole 41, asillustrated, to releasably position the chain in slot 42. With thisarrangement then limiting chain 40 may be positionedwithany particularlink retained by the chain-fastening plate. An extension spring 45extends between the medial portion of chain 40 and the medial portion ofangle crosspiece 17 of the body structure to prevent the chain frombecoming fouled if excessive slack be created therein during passage ofa boat over the guiding structure.

Having thusly described the structure of my invention, its operation maynow be understood. I

Two guide structures, preferably one the mirror image of the other, areformed according to the foregoing specification and mounted in pairedopposed fashion on the rearward part of an ordinary boat trailer frame,as illustrated in FIG. 1, with each guide arm angling upwardly andoutwardly to form somewhat of a V shaped area therebetween. Thepositioning of-the guide structures should be such that they are eachsubstantially the same distance laterally outwardly from the centerlineof the trailer, but exact distance of lateral positioning is notparticularly critical because of the adjustable nature-of the guide. Ingeneral, however, when the guides are normally biased, upwardlyextending, position they should be relatively close to each other sothat they will contact the forward 'sharper portion or bow of a boat.The body structures of the guides may be attached to the trailer frameby any of the normal means known in the mechanical arts, but preferablywith metal structures by welding.

With the guides of my invention in place on the trailer, each guide armis then adjusted to a substantially vertical, slightly laterally angled,position by appropriate positioning of chain 40 relative chain-fasteningplate 18 and tension in torsion spring 33 is appropriately adjusted tomaintain sufficient force upon guide arms 26 to allow them to maintain aboat in substantially aligned position when passing between the guidearms. In this fashion the device is then ready for the loading of a boatin the habitually familiar fashion.

To accomplish the loading operation the trailer is backed on a slopingramp into the water whereon the boat to be loaded is floating. Theforward portion or bow of the boat is generally attached by a cable (notshown) to winch 46 in the forward portion of the boat trailer and theboat while still floating is drawn by this winch toward the trailer, Asthe forward portion of the boat approaches the trailer, it is contactedon either side of the bow by the paired opposed guides of my inventionand the portion contacted by these guides is maintained in alignmentrelative the rear portion of the trailer. This condition continues asthe boat is pulled upon the trailer until such time as it is in finalresting position upon the trailer with keel carried by the normal medialkeel rollers 47. At this time the trailer may be removed from the waterand the boat finally fastened to the trailer in the habitually familiarfashion.

In the loading operation it is to be noted that the boat will generallybe substantially floating and will have forces applied to it at threepoints, that is its forwardmost portion by the cable carried by boatwinch 46 and in paired opposed rearward spots by contact of rollers 27with the hull as it passes thereover. With this arrangement of forcesthen, a boat is required of necessity to remain substantiallysymmetrical relative the trailer.

It is further to be noted from the foregoing structure that during thepassage of the boat over the guide rollers, as the hull broadens or asmore weight is placed upon the guide rollers, they will by reason oftheir vpivotable mounting and mechanical bias move downwardly toaccommodate the changing crossnsectional configuration of the boat andthe greater amount of weight as more weight is transferred to thetrailer by reason of less flotation.

The foregoing description of my invention is necessarily of a detailednature so that a specific embodiment of it might be set forth asrequired, but it is to be understood that various modifications ofdetail, rearrangement and multiplication of parts may be resorted towithout departing from its spirit, essence or scope.

Iclaim: 1. Guide structures to aid in flotation positioning of a boatupon an elongate boat trailer, comprisingz' paired opposed housingstructures carried in laterally symmetrical position in the rear medialpart of a boat trailer;

upwardly extending, paired opposed elongate guide arms pivotably mountedin perpendicularly projecting bushings, carried by each housingstructure, to allow laterally downward motion of the guide arms;

independent mechanical biasing means communicating between each guidearm and each associated housing to bias the guide arm to a normallyupward position; and

motion limiting means communicating between the guide arms and thehousing preventing motion of the guide arms past vertical.

2. Guide structures to aid in flotation positioning of a boat upon anelongate boat trailer, comprising:

paired opposed housing structures carried in laterally symmetricalposition in the rear media] part of a boat trailer;

upwardly extending, paired opposed elongate guide arms pivotably mountedin perpendicularly projecting bushings, carried by each housingstructure, to allow laterally downward motion of the guide arms;

independent mechanical biasing means communicating between each guidearm and each associated housing to bias the guide arm to a normallyupward position; the biasing means comprising a helical spring carriedabout the guide arm bushing in axial alignment therewith, the springhaving one end communicating with the guide arm and the other endcommunicating with an adjustment bolt carried in one of a plurality ofholes in the body structure to provide adjustable biasing of the guidearm; and

motion limiting means communicating between the guide arms and thehousing preventing motion of the guide arms past vertical.

3. The invention of claim 2 wherein the motion limiting means is furthercharacterized by a chain communicating between the upper portion of theguide arm and a chain fastening plate carried by the body structure, thelatter communication being of adjustable nature.

4. The invention of claim 2 wherein the guide arms are furthercharacterized by:

rotatably mounted rollers carried in their upper portion to rollablyguide a boat therealong; and

rigid elongate guides extending thereabove to prevent lateral passage ofa boat thereby.

